1. Field of the Invention
The present invention pertains generally to the field of illumination, and more particularly to electrical illumination systems that may be selectively controlled intuitively and with prior art controls to provide variations in both intensity and color temperature.
2. Description of the Related Art
Humans have many gifts that are relatively unique in the animal kingdom, particularly when considered in aggregate. Among these are the abilities to function through many hours in a twenty-four hour day, and the ability through many diverse and sometimes complex implements and contrivances to also exert great control over our environment. As we have used these implements to satisfy needs and desires, one notable and almost universally demanded application is the provision of illumination. A typical adult may spend two-thirds of a twenty-four hour day awake, or about sixteen hours. In contrast, the average time for natural illumination from the sun is only slightly more than half of that same twenty four hour period, or slightly more than twelve hours including the partially illuminated time of dawn and dusk. This means that there may exist an average of about three and a half hours of time awake for which there is no or only very minimal illumination provided by the sun.
While humans have many gifts, there are many creatures in the animal kingdom that have far better eyesight through the night hours. In fact, the productivity of many humans is severely inhibited without some form of additional light during the night. For many centuries, humans relied heavily upon combustible matter to meet this need, quite simply burning things from their surroundings to provide desired illumination. Based upon early cave drawings and the like, it is thought that early humans in pre-recorded time burned wood and other plant matter in simple fires to both cook and provide illumination during the otherwise darkness of the night. This practice evolved over time into much more refined contrivances such as lanterns that burned various oils and candles made from various waxy materials.
The light from these combustible sources is referred to as thermal radiation, and is sometimes described by and known as black body radiation. One way of describing light that is emitted from a source, which is in common use today, is referred to as the color temperature of the light. When an ideal black body radiates light, the hue or color of the light changes with changes in the temperature of the black body radiator. As the light source gets hotter, the color of the light will shift towards the white or blue, while a lower temperature will yield a more yellow or reddish hue. As one simple example, when a blacksmith heats iron in a furnace, the iron will first turn “red hot”, but if heated to an even higher temperature, the iron will turn progressively to a more yellow color and even “white hot”. Likewise, embers from a wood fire may glow a red color, burning slowly at a relatively lower temperature. In contrast, the flames from an open wood fire may appear yellow. If that same wood fire is fed with sufficient oxygen, such as in a blast furnace or sometimes at the tips of the flames, the flames may even turn to a blue hue.
The unit of measurement for color temperature is degrees Kelvin. Color temperatures in the range of approximately 6,000 degrees Kelvin have a hue very similar to bright, midday sun. However, as the sun rises and sets, the characteristically more reddish appearance will lower the color temperature to less than 2,000 degrees Kelvin. As may be apparent then, a very hot open wood fire may be somewhere between that of daylight and sunset, while as the fire burns down to embers the color will shift to that of the final minutes of sunset.
About a century and a half ago, which is a very small amount of time when compared to recorded history and even smaller when compared to postulated existence of humans, electricity and electrical machinery began to come into more general use and acceptance, permitting various electrical lamps to replace sources of light that relied upon combustible materials. While it may have been debated in the early days of electricity whether electrical lights were safer or better than combustion lights, in a matter of only a few decades, better electrical machinery was developed that both lowered the cost of illuminating with electricity and also greatly improved the safety of such illumination sources over the older combustible sources.
One of the characteristics of these early electrical lights that we now refer to as incandescent lamps is the fact that they rely upon heat as the source of visible radiation, just as the combustible materials do. The heat source, typically a tungsten filament, operates at a temperature of around 2,400 degrees Kelvin. This temperature is significantly lower than the color temperature of the midday sun, instead corresponding to the light of the early morning and later evening. Consequently, the light from an incandescent lamp is generally both dimmer and more yellow than that of broad daylight. In fact, these incandescent lights create an ambience very similar to that of a wood fire relied upon by our distant ancestors. However, since these lights are very hot, they also dissipate a large amount of heat to their surroundings, just as the combustible materials do. This means they are not very efficient at converting electricity to light, and instead also create much waste heat.
Only a few decades after the introduction and early use of the incandescent lights, electric lights that produced light by other means known as luminescence were successfully commercially introduced. A particularly noteworthy type of such lights is known of as the gas discharge lamp, specific exemplary instances of which are known of as fluorescent lights, neon lights, and mercury vapor lamps. In these types of lamps, electricity excites gas contained in the light bulb causing it to emit light. Since these lights do not produce light from a heat source, the light emissions are often in very narrow bands of wavelengths or colors that are dependent upon the mixture of gasses and pressures used in the design and construction of the light. Since heat is not required to produce light, and instead the ionization of the gas is the source, there is typically less energy lost in the process. This in turn means these lights are often much more efficient at producing light than the incandescent lamps and other heat sources, meaning they require less electricity to operate. Finally, many of these gas discharge lights can also be designed for substantially longer operation without replacement than incandescent bulbs. Consequently, in the last half century, and particularly in the last few decades, these gas discharge lights have found very wide application, including wide area illumination such as street and yard lights, home and commercial applications through the implementation of the tubular fluorescent lighting, and through the advent of smaller compact fluorescent lights the direct replacement of many incandescent lights in many household and work fixtures.
While these gas discharge lamps offer many benefits, they are not without limitation. One such limitation is a result of the narrow bands of wavelengths emitted by the gas ionization. Since the human eye is sensitive to many different wavelengths, or colors, of light, illumination at only one or a few wavelengths can cause visual disturbance. In contrast, a thermal light source or ideal black body radiator may generally provide nearly perfect color rendering to humans across a full spectrum of wavelengths. As an example, many street lights use either high pressure mercury or sodium vapor lamps. While these lamps are quite efficient at generating visible light, the wavelengths of emitted light fall in only a few very narrow bands. As a result, they are often perceived as being “eerie” by many persons. As an example, mercury vapor street lamps tend to make a healthy person appear “bloodless” due to the lack of the red hues in the light. Since the light emitted from these lights does not distribute across the spectrum the way an incandescent lamp or other heat source does, a Correlated Color Temperature, or simply CCT, is assigned that correlates the light emission to the closest color temperature of a black body radiator.
To overcome this limitation regarding color rendition and color temperature, various fluorescent materials have been identified and developed that may be incorporated into these gas discharge lamps. Fluorescent materials, which may sometimes be referred to as phosphors, convert some of the narrow bands of light into different wavelengths, allowing designers to shift the hue of the light and also broaden the range of wavelengths emitted by the light. These fluorescent lights have been designed for and accepted in nearly every location, and are sometimes very much preferred over incandescent lights.
Another limitation has been the dimming of fluorescent lights. At some level of emission, the gas discharge will extinguish. This energy level is often higher than that required in an incandescent bulb, meaning the fluorescent light must be kept at a higher brightness level than an incandescent bulb. Furthermore, with an incandescent bulb, the typical electronic circuit used to accomplish the dimming, such as a TRIAC or SCR that simply blocks a part of the voltage cycle, will not work properly with a fluorescent bulb. This means that for many years, it was not possible to dim fluorescent bulbs using ordinary and standard light dimmers. Once again, and particularly recently, various artisans have developed special electronic circuits that allow some fluorescent bulbs to be dimmed using standard light dimmers.
Nevertheless, fluorescent lights continue to suffer from another very notable deficiency. When an incandescent light is dimmed, not only is there a decrease in the amount of light emitted, commonly measured in Lumens, but there is also a shift in the color temperature. This is from the reduced energy input causing the filament to operate at a lower temperature. This shift in the color temperature will be perceived as a shift more towards the red, which resembles that of the setting sun or of the dying embers of a fire. Because the phosphors of a fluorescent light bulb are what determine the wavelength of emitted light, there is simply no opportunity for the fluorescent light to emulate this shift in color temperature that occurs with incandescent bulbs and naturally in a dying fire or setting sun.
Through this evolution in lighting, there has also been a gradual evolution in the science of understanding human cycles that vary with periods of day and night. Some of these may simply be referred to as diurnal or nocturnal cycles, where light and darkness are known to trigger various events. However, a more elemental or fundamental cycle, commonly referred to as the circadian cycle, has also been identified and extensively studied in humans and animals. The circadian cycle is an approximately twenty-four hour cycle that in humans involves rhythmic variations in the production of various powerful hormones in the body, changes in blood pressure, mental alertness, body temperature, and even reaction time. By definition, a circadian cycle must be endogenous, meaning it will be sustained with or without daily exposure to daytime and nighttime, and it must be entrained to the local environment by external cues, such as light and temperature. Consequently, when a person travels to a distant location in a very different time zone, the endogenous nature of the circadian cycle means that the person will still want to sleep on their home schedule. However, over a period of days or weeks, the person will receive enough cues from the new location, commonly referred to as zeitgebers, to shift their circadian cycle and become entrained in the timing of the new location. The interim period can be extremely disruptive, and is common among those who travel rapidly and distantly around the earth. Consequently, it is commonly referred to as “jet lag”.
More recently, unintended entraining of the circadian rhythm has been discovered to occur from zeitgebers such as the intensity and color temperature of indoor lights that a person is exposed to. So, for exemplary purposes, working late hours in front of a modern computer screen having a very high Correlated Color Temperature (CCT), shifted to the white and blue end of the spectrum, can confuse and disrupt a person's circadian rhythm. The person's body will sooner or later react to the high CCT as though the person is being exposed to midday sun, and this signal will then lead to a shift in the person's circadian rhythm. If in fact the person is viewing this screen during midday, then there is no adverse consequence. However, if instead the person is exposed to this high CCT light in the twilight or night time, this can be very disruptive to the circadian cycle and create the symptoms of jet lag, or worse, in people who have not traveled at all and who are otherwise healthy. In more minor instance, this exposure may simply manifest in poor sleep, or a lack of energy during the day. In severe instances, the deceptive signal may lead to a partial or complete disruption of vital hormone production, sleep, or other adverse condition. Further, continued long term exposure is thought by some researchers to also be associated with much more serious adverse health impact.
With the relatively more recent advent of Light Emitting Diodes (LEDs) having higher power and light generation capabilities, and the provision of LEDs of various colors and hues, several ingenious artisans have overcome many of the limitations of the prior art in positive and beneficial ways. Two exemplary patents, the teachings and contents which are incorporated herein by reference, disclose dimmable lights that provide simultaneous color temperature change: U.S. Pat. No. 8,633,650 by Sauerlaender, entitled “Dimmable light source with light temperature shift”; and U.S. Pat. No. 7,288,902 by Melanson, entitled “Color variations in a dimmable lighting device with stable color temperature light sources”. These two patents provide LEDs having different color emissions, and control the intensity of the different LEDs based upon the extent of dimming. As a result, these lights do emulate the incandescent lights and combustion lights of the prior art much more nearly. As beneficial as these may be, they too have limitation. While the sunset combines both a shift in color temperature to a lower color temperature and a shift in intensity to a lower intensity, the intensity of the light from the sun is often still many times greater than that produced by electric lighting. As a result, the present invention recognizes the desirability of selectively providing an optimum color temperature, independently of requiring a shift in intensity.
Other artisans have recognized the desirability for providing greater control over the characteristics of a light source. Exemplary patents, the teachings and contents which are incorporated herein by reference, include: U.S. Pat. No. 6,016,038 by Mueller et al, entitled “Multicolored LED lighting method and apparatus”; and U.S. Pat. No. 7,845,823 by Mueller et al, entitled “Controlled lighting methods and apparatus”. These lighting systems provide an exemplary array of features and capabilities that may be selected, including color temperature and intensity. However, these systems are also very complex. Consequently, cost is prohibitive for some consumers, and complexity of operations is prohibitive for other consumers. Unfortunately, as a result these systems have not achieved the level of commercial success that was anticipated by many.
Recognizing the desirability of control over a lamp, without the need for a separate computing device or smart phone, two additional patents propose the provision of switch control directly into a lamp. These two exemplary patents, the teachings and contents which are incorporated herein by reference, include: U.S. Pat. No. 8,143,807 by Hsieh et al, entitled “Color temperature controller and color temperature control method of light emitting diode”; and U.S. Pat. No. 8,278,827 by Ku et al, entitled “LED lamp”. While these inventions alleviate the need for external control apparatus, the controls for these lights are non-standard, and for many persons may generate confusion over how to operate and control the light source.
Further patents and published patent applications seek to incorporate control over LED light characteristics using a prior art wall switch or dimmer apparatus. Exemplary patents, the teachings and contents which are incorporated herein by reference, include: U.S. Pat. No. 8,441,202 by Wilson et al, entitled “Apparatus and method for LED light control”; U.S. Pat. No. 8,736,183 by Chao, entitled “LED driver capable of controlling color/color temperature with a power carrier”; 2012/0242247 by Hartmann et al., entitled “Operation of an LED Luminaire Having a Variable Spectrum”; 2013/0200814 by Chen et al., entitled “LED lighting apparatus and dimming method thereof”; and 2014/0210357 by Yan et al., entitled “Adjusting Color Temperature in a Dimmable LED Lighting System”. These artisans present ingenious techniques for controlling various characteristics of the lights directly from a prior art light switch and dimmer. As innovative as these are, they operate with sensitive electronics coupled directly at the line voltage output from the light switch and dimmer, in some cases necessitating the insertion of various opto-isolators, special voltage regulators, and the like. Further, these also necessitate the provision of a custom driver. Unfortunately, there are literally thousands of LED panels, and many different available drivers. While some manufacturers have standardized to particular standard drivers, there are still others that manufacture a driver associated with and in fact required for a single one of their panels. Consequently, these prior inventions are believed to be deficient both from a safety and security perspective, and also from the need to either provide a custom LED panel and driver, thereby limiting these inventions to new production only and no retrofitting, or the need to manufacture and inventory many variants for each distinct LED panel driver, a daunting task at best and financially impractical for many current commercial projects.
Two exemplary patents, the teachings and contents which are incorporated herein by reference, disclose single power switch controlled color change apparatus, but without a dimmer: U.S. Pat. No. 6,685,339 by Daughtry et al, entitled “Sparkle light bulb with controllable memory function”; and U.S. Pat. No. 8,162,517 by Lee, entitled “Lamp”.
Another assortment of exemplary patents, the teachings and contents which are incorporated herein by reference, also disclose wall switch controlled lighting modes: U.S. Pat. No. 4,634,957 by Hollaway, entitled “Remotely controlled light flasher”; U.S. Pat. No. 4,695,739 by Pierce, entitled “Multi-function switch-controlled lamp circuit”; U.S. Pat. No. 4,777,384 by Altenhof et al, entitled “Source voltage triggered timer”; U.S. Pat. No. 4,540,984 by Waldman, entitled “Energy saving control circuit for a light switch and a method therefor”; U.S. Pat. No. 5,030,890 by Johnson, entitled “Two terminal incandescent lamp controller”; Re 35,220 by Johnson, entitled “Two terminal controller”; U.S. Pat. No. 6,700,333 by Hirshi et al, entitled “Two-wire appliance power controller”; and U.S. Pat. No. 9,119,245 by Yang, entitled “LED driving system for switched dimming control and dimming method using the same”.
Another collection of exemplary patents, the teachings and contents which are incorporated herein by reference, disclose wall switch controlled switching between two light sources: U.S. Pat. No. 4,322,632 by Hart et al, entitled “Remote load selector”; U.S. Pat. No. 4,480,197 by Hollaway, entitled “Multiple load switching circuit”; and U.S. Pat. No. 4,767,968 by Geanous et al, entitled “System for controlling the operation of electrically powered apparatus”.
In addition to the aforementioned patents, Webster's New Universal Unabridged Dictionary, Second Edition copyright 1983, is incorporated herein by reference in entirety for the definitions of words and terms used herein.